diff --git a/src/liballoc/collections/vec_deque.rs b/src/liballoc/collections/vec_deque.rs
index 091b068b0b2..a3b61f1f4a5 100644
--- a/src/liballoc/collections/vec_deque.rs
+++ b/src/liballoc/collections/vec_deque.rs
@@ -50,6 +50,7 @@ const MAXIMUM_ZST_CAPACITY: usize = 1 << (64 - 1); // Largest possible power of
 /// [`pop_front`]: #method.pop_front
 /// [`extend`]: #method.extend
 /// [`append`]: #method.append
+#[cfg_attr(not(test), rustc_diagnostic_item = "vecdeque_type")]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct VecDeque<T> {
     // tail and head are pointers into the buffer. Tail always points
diff --git a/src/liballoc/string.rs b/src/liballoc/string.rs
index 80fa8139915..f3fe1adebb1 100644
--- a/src/liballoc/string.rs
+++ b/src/liballoc/string.rs
@@ -278,6 +278,7 @@ use crate::vec::Vec;
 /// [`Deref`]: ../../std/ops/trait.Deref.html
 /// [`as_str()`]: struct.String.html#method.as_str
 #[derive(PartialOrd, Eq, Ord)]
+#[cfg_attr(not(test), rustc_diagnostic_item = "string_type")]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct String {
     vec: Vec<u8>,
diff --git a/src/libstd/collections/hash/map.rs b/src/libstd/collections/hash/map.rs
index 706b388f783..e6da7426eb4 100644
--- a/src/libstd/collections/hash/map.rs
+++ b/src/libstd/collections/hash/map.rs
@@ -198,6 +198,7 @@ use crate::sys;
 /// ```
 
 #[derive(Clone)]
+#[cfg_attr(not(test), rustc_diagnostic_item = "hashmap_type")]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct HashMap<K, V, S = RandomState> {
     base: base::HashMap<K, V, S>,
diff --git a/src/libstd/collections/hash/set.rs b/src/libstd/collections/hash/set.rs
index 1ad99f03703..c1a57f2ce61 100644
--- a/src/libstd/collections/hash/set.rs
+++ b/src/libstd/collections/hash/set.rs
@@ -105,6 +105,7 @@ use super::map::{self, HashMap, Keys, RandomState};
 /// [`PartialEq`]: ../../std/cmp/trait.PartialEq.html
 /// [`RefCell`]: ../../std/cell/struct.RefCell.html
 #[derive(Clone)]
+#[cfg_attr(not(test), rustc_diagnostic_item = "hashset_type")]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct HashSet<T, S = RandomState> {
     map: HashMap<T, (), S>,
diff --git a/src/libstd/sync/mutex.rs b/src/libstd/sync/mutex.rs
index 0cb16b19d73..797b22fdd12 100644
--- a/src/libstd/sync/mutex.rs
+++ b/src/libstd/sync/mutex.rs
@@ -108,6 +108,7 @@ use crate::sys_common::poison::{self, LockResult, TryLockError, TryLockResult};
 /// *guard += 1;
 /// ```
 #[stable(feature = "rust1", since = "1.0.0")]
+#[cfg_attr(not(test), rustc_diagnostic_item = "mutex_type")]
 pub struct Mutex<T: ?Sized> {
     // Note that this mutex is in a *box*, not inlined into the struct itself.
     // Once a native mutex has been used once, its address can never change (it